Ejector in series



Sept. 30, 1930. I J, G w 1,777,239

EJECTORIN SERIES Filed Nov. 10, 1928 2 Sheets-Sheet 1 FIG :1.

J2me; & 746?.

Sept. 30, 1930. v J, WEIR 1:777339 EJECTOR IN SERIES Filed Nov. 10, 1928 2 Sheets-Sheet 2 FIG 2Q Patented Sept. 30, 1930 UNITED STATES PATENT OFFICE JAMES GEORGE WEIR, or cArHcAnr, GLASGOW, scoirtannessrcnon r0 e. & :r. WEIR, LIMITED, or QATHCART, GLASGOW, SCOTLAND EJECT'OB IN SERIES Application filed November 10, 1928, SeriaLNo. 318,466, and in Great Britain December 9, 1927.

The present invention relates to the employment in series of ejectors in which the aspirating or impelling fluid is steam and/or air.

There has already been employed an arrangement of ejectors in series in which some of the discharge from one of the ejectors is employed as aspirating or impelling fluid in a preceding ejector, that is, in an ejector nearer to the vessel being evacuated by the ejector system. 7

The objection to the arrangement described in the specification aforesaid is that the steam which is taken from the discharge of an ejector for use in a preceding ejector has mixed with it a large percentage of air. This is objectionable. It is the object of the present invention to avoid this objection.

It may be stated in brief that the present invention consists in an arrangement of two or three e ectors 1n serles in which the d1scharge (or some of it) from the secondand/ or third ejector of the series is passed through a condenser-evaporator apparatus in which e the steam, (or much of it), is condensed, the

air (or most of it), liberated, and the condensate, (or a large portion of it), led back to the same apparatus and evaporated by the heat given up by the steam in condensing,

and the generated steam led back to the primary or second ejector and employed as the aspirating or impelling fluid in that ejector.

The invention will be defined in the an nexed claims. It can, however, be best explained by describing with the aid of draw ings an example of the carrying of the invention into effect.

The accompanying drawings which are diagrammatic are provided to illustrate the carrying of the invention into effect, each illustrates a convenient manner of executionFig. 1 in a case where two ejectors in series are employed and Fig. 2 where there are three ejectors in series.

Referring in the first place to Fig. 1, a is the primary or first-stage ejector. c is the suction of the same from the vessel being evacuated, e. g. the condenser of a steam turbine. 72 is an inter-condenser of the surface type employed to condense (as far as possible) the aspirating or impelling steam of'the nozzles 79 and the steam drawn in at c (withthe air). Theair and uncondensed steam from the condenser 22 are led alongthe pipe (7 to the secondary or second-sta e ejector f. e is a drain, back to the vesse being evacuated.

Live steam 1s employed as asplratlng or impelling fluid, in the nozzle 9 of the secondary ejector f. The discharge from this ejector is into the end-box m of the condenser-evaporator h. This is a tubular apparatus like a surface steam condenser, but with the steam inside the, tubes and the water outside the tubes. The steam is condensed, or largely condensed, in the tubes h. The steam, air, and condensate pass through the tubes into the end-box n. The uncondensed steam and the air may be discharged through the pipe 6 to the atmosphere or they may be led to a supplementary condenser 41' where the steam (or most of it) is condensed for the sake of recovering the feed water. The condensate is discharged by way of the pipe 7' into the water space of the apparatus.

A trap a is arranged on the pipe 7' to prevent the passage of steam or air.

The heat given up by the steam in condensing in h is employed to evaporate the water outside the tubes; and steam is generated approximately equivalent in amount to the steam condensed. The steam evaporated is discharged by the pipe 0 to the nozzles p of the primary ejector a to be there employed as the aspirating or impelling fluid.

The steam generated in h is air-free unless @LiA arran as-actor, an, nter condenser for condensing I I the said e ectOr, a secend-. stage eJect-or, apipe connection whereby the I in Figure 1. An intermediate stage has been interposed between the first and last stages. The aspirating or impelling fluid for this, the second sta e, is obtained (by the pipe m) from the con enser-evaporator of the last stage. This ego lid stage '2 is rovided with a condenser-evaporator w similar to the condenser-evaporator h. The air (with unconsense steam) m this o den er-ev ator w is drawn, as shown, by way of the pipe u, to the last stage ejector.

The supplementary condenser 11 shown in Figure 1 is not shown in Figure 2 as receiving the dischar e from the pipe 25. Such a co enser may e provided, if desired, but, w; three stages, as in the present case, it ma n'ot be necessary. The air, tt; e stea'm it contains, may be discharged dine; to atmosphere. 9 r a three-stage arrangement, the steam froin the condenser-evaporator of the last sta emay, if desired, be employed as the gspl fatihg or impelling fluid'in the first-stage nsteadof in the second-stageejector. :su'ch a, case the second stage would not be flii' h l 1 i i r i rov ded with a condenser-evaporator but I it); simple condenser like the condenser 12 of thefirst stage. Having thus described my invention, what Ipla1m as new and desire to secure by Let t'rs fF-atent is 2-5 p gement and combination of a first-stage e'ctors in series comprisin i egec'tor, an, inter-condenser or condensing 35 t 'eisteam from the said ejector, a se'condejector, a pipe-connection whereby the second-stage ejector can withdraw the pair and uncondensed steam from the said inter-co denser, a condenser evaporator for condensing the steam from the said secondstage ej'ector and subsequently re-evaporat= ing theresulting water of condensation, and ealis fordischarging the air contained, in gishtearn between the "said condensing and the said rte-evaporating. H g V 12. nagram 'ment and combination of t am f m said second-stage e]ector can withdraw the air and uneondensed steam from the said inter-condenser, a condenser-evaporator for condensing the steam from the said secondstage ejector and subsequently re-evaporati'ng the resulting water of condensation,

ineans for discharging the air contained in this steam between the said condensing and the said re-evaporating, the said condenserlar body between them having a steam space iind a water space, and a duct for the dis "btfasgge of the said water-of-conden's'ation with what i,777,2se

tor, an inter-condenser for condensing the steam from the said e ector, a second-stage ejector, a pipe connection whereby the said second-stage ej ector can withdraw the air and uncondensed steam from the said inter-condenser, a condenser-evaporator for condensing the steam from the said second-stage ejector and subsequently re-evaporating the resulting water of condensation, means for discharging the air contained in this'steam between the said condensing and the said reevaporating, the said condenser-evaporator being formed with a receiving end-box and a delivery end-box with a tubular body between them having a steam space and a water space, a duct for the discharge otthe said water-'of-condensati on from the said delivery end-box to the said water space, and a steam and air trap on the said duct.

4. arrangement and combination of ejectors in series comprising a first-stage ej ector, an inter-condenser tor condensing the steam from the said ejector, a second-stage ejectorfa pipe connection whereby the said second-stage ejector can withdraw the air and nncondensed steam from the said inter-conconnection whereby the'said thirc stage egector can withdraw the air and uncondenscd steam from thesaid condenser-eva'porator.

5. An arrangement and combination oi ejectors in series comprising a first-stage e ector, an inter-condenser for condensing thesteam from the said ejector, a second sta e, ejector, a pipe connection whereby the "sa1 second stag'e e cctor'canwithdraw the air and uncondensed steam from the said nter condenser, a condenser-evaporator tor condensing the steam from the said secondstage ejector and subsequently re-evaporat 'ing the resulting water of condensation, means for discharging the air eontained'in this steambetween the said condensing and the said re-evaporating, a tliin'l-stageejector, a pipe connection whereby the said third- "stage e]ector can withdraw the air and unco nde nsed steam from the said condenserevaporator, condenser-evaporator i or con- (lensing the steam from the said third-stage U V r I ejectora'nd subsequently re-ev'aporating the evaporator being formed with a receiv ng end-box and a delivery end-box wlth a tubu- "6. An arrangement and combination of ejectors in series comprising a first-stage ejector, an inter-condenser for condensing the steam from the said ejector, a secondstage ejector, a pipe connection whereby the said second-stage ejector can withdraw the air and uncondensed steam from the said inter-condenser, a condenser-evaporator for condensing the steam from the said secondstage ejector and subsequently re-evaporating the resulting water of. condensation, means for discharging the air contained in this steam between the said condensing and the said re-evaporating, the said condenserevaporator being formed with a receiving end box and a delivery end box with a tubular body between them having a steam space and a water space, a duct for the discharge of the said water-of-condensation from the said delivery end-box to the said water-space, a third-stage ejector, a pipe connection whereby the said third-stage ejector can Withdraw the air and uncondensed steam from the said condenser-evaporator, a condenser-evaporator for condensing the steam from the said third-stage ejector and subsequently re-evaporating the resulting waterof-condensation, means for discharging the air contained in this steam between the said condensing and the said re-evaporating, the said last-mentioned condenser-evaporatorbeing formed with a receiving end box and a delivery end box with a tubular body between them having a steam space and a water space, and a duct for the discharge of the said last-mentioned water-of-condensation from the said last-mentioned delivery end box to the said last-mentioned water space.

7. An arrangement and combination of ejectors in series comprising a first-stage ejector, an inter-condenser for condensing the steam from the said ejector, a second-stage ejector, a pipe connection whereby the said second-stage ejector can withdraw the air and uncondensed steam from the said intercondenser, a condenser-evaporator for condensing the steam from the said second-stage ejector and subsequently re-evaporating the resulting water of condensation, means for discharging the air contained in this steam between the said condensing and the said reevaporating, the said condenser-evaporator being formed with a receiving end-box and a delivery end-box with a tubular body between them having a steam space and a water space, a duct for the discharge of the said water-of-condensation from the said delivery end-box to the said water space, and a steam and air trap on the said duct, a thirdstage ejector, a pipe connection whereby the said third-stage ejector can withdraw the air and uncondensed steam from the said condenser-evaporator, a condenser-evaporator for condensing the steam from the said thirdstage ejector and subsequently re-evaporating the resulting water-of-condensation,

means for discharging the air contained in this steam between the said condensing and the said re-evaporating, the said last-men- I tion.

JAMES GEORGE WEIR. 

